Modified Viologen- and Carbonylpyridinium-Based Electrodes for Organic Batteries

Efficient electrochemical energy storage has been identified as one of the most pressing needs for a sustainable energy economy. Inorganic battery materials have traditionally been the center of attention, with the current state-of-the-art device being the lithium-ion battery. Recent pursuits have led to organic materials for their beneficial chemistry and properties, but suitable materials for organic batteries are still few and far between. This Spotlight on Applications highlights two intriguing pyridinium-based organic materials, modified viologens and carbonylpyridiniums, that have both been successfully employed in electrode materials for solid-state Li-ion-type organic batteries (LOBs). We first provide an overview of the inherent electronic properties of each building block and how they can effectively be modified while maintaining or enhancing their desirable electrochemical properties for practical applications. We then describe a range of different material designs for a battery context and their application in various organic device settings, with some examples showing competitive performance with traditional Li-ion batteries.